Arrangement for automatically placing weights on molds and removing them from same



Apnl 15, 1958 E. BUHRER 2,830,341

ARRANGEMENT FOR AUTOMATICALLY PLACING WEIGHTS 7 ON MOLDS AND REMOVING THEM FROM SAME Filed Nov. 3, 1955 United States Patent GEMENT FOR AUTOMATICALLY PLAC- ING WEIGHTS ON MOLDS AND REMOVING THEM FROM SAME Erwin Biihrer, Schatfhausen, Switzerland, assignor to Georg Fischer Aktiengesellschaft, Schatfhausen, Swit zerland, a Swiss company Application November 3, 1955, Serial No. 544,794

Claims priority, application Switzerland August 29, 1955 3 Claims. (Cl. 22-112 The present invention relates to an arrangement for automatically placing weights on molds before casting and for lifting and returning said weights after casting, the molds being disposed on a moving conveyor and the weights being placed, lifted and returned by means of a conveyor running over a closed circuit.

A known method is to arrange on a conveyor for molds supports from which are suspended weights which are placed on the molds'or lifted from same by means of a threaded spindle, rack-and-pinion actuation or lifting and dropping cams. Another known method is to secure the weights to an endless conveyor by means of links which are flexible in every direction and to arrange said weights above a mold conveyor in such a way that they are lowered on to the molds before casting and raised again from them after casting.

All these arrangements have the drawback that they occupy the space above the molds along the entire casting line. A further known method is to transport molds on an overhead conveyor, the frame of which is rotatable about a vertical axis, while a second overhead conveyor carries weights, places same on the molds before casting, and I down cams approximately in the centre of the straight sections. Said roundabout has controlled mechanisms and compressed-air cylinders which, on the one section, lower casing parts and weights over and on to flaskless molds and, on the other section, remove same again.

The last-named embodiments have the disadvantage that they call for complicated and extensive equipment and that the mold conveyor must, after casting, be

brought back into the vicinity of the mold conveyors section before casting. These embodiments are therefore mainly used with fiaskless molds, the casing part being also placed and lifted at the same time.

The present invention difiers from the constructions mentioned above in that the conveyor for the weights moves downwards past the conveyor for the molds when placing the weights and upwards past said conveyor when lifting the weights.

Ina particularly suitable embodiment the two conveyors cross at an acute angle in such a way that the speed component of the conveyor for the weights is, in the direction of movement of the conveyor for the molds, exactly the same as the latters speed.

A typical embodiment of the invention is illustrated in the attached drawing, in which:

2,830,341 Patented Apr. 15, 1958 Fig. 1 is a diagrammatic view of a conveyor for weights to be positioned on molds,

Fig. 2 is a section through Fig. 1 taken along the line 11-11,

Fig. 3 shows a supporting frame according to shown on an enlarged scale, and

Fig. 4 is a view taken in the direction of arrow IV in Fig. 3.

In Figs. 1 and 2, 1 designates conveyor trucks which carry molds 2 and move in the direction of arrow 3. The conveyor means for the weights 4 consists of two parallel conveyor chains 5 provided with uniformly spaced weightsupporting frames 6, the chains being disposed on opposite sides of the conveyor means 1 for the molds 2 (see Fig. 2). Weights 4, which are suspended from each conveyor chain 5 via supporting frames 6 by means of crossbars 7, move in the direction of arrow 8. The weights 4 suitably consist of heavy ceramic material having a good resistance to changes in temperature, such as zirconium oxide, corundum or the like. Additional weights 28, made of metal, can be placed on the weights 4. The supporting frames 6 are'arranged to oscillate on the conveyor chains 5 with bolts 22. To prevent the cross-bars 7 from sliding off the supporting frames 6, said cross-bars have a disk 23 at each end. Located on the cross-bars 7 are oblique lugs 24 in which the weights 4 are clamped and held by means of a wedge 25. In the sections 9, 10, 12 and 13 the conveyor chains 5 are guided in rails over rollers 14. The conveyor is driven through shaft 15, gear 16, shaft 17 and sprocket wheels 18. The shaft 15 is mechanically connected to the drive (not illustrated) of the conveyor trucks 1. The conveyor chains 5 are run over guide wheels 19 in the usual manner. The conveyors for the weights and for the molds cross at an acute angle in such a way that the speed component of the conveyor for the weights is, in the direction of movement of the conveyor for the molds, exactly the same as the latters speed. The two conveyors, the one for the weights and the one for the molds, cross at an acute angle, both when the weights are being placed and when they are being lifted, at least over a distance which corresponds to the movement of the weights from the level of the highest mold down to the molds bearing surface or from the latter up to the highest mold.

The arrangement operates as follows: the weights 4 are placed on the molds 2 in the section 9 and, weighting the said molds, move in the direction of arrow 3 towards the section 10. The conveyor chains move in the direction of arrow 11, in a lower position without weights, towards the section 10. Between section 9 and section 10 the molds 2, while they are being moved along in the direction of arrow 3, are cast and cooled until the weights 4 can be lifted off again at section 10. The weights 4, suspended from the conveyor chains 5, move in the direction of arrow 8 back to the section 9. Arrow 2t shows the speed of the conveyor chains when circulating in the direction of arrows 8 and 11 respectively. The horizontal speed component 21 over the sections 10 and 9 respectively corresponds to the speed at which the conveyor trucks move in the direction of arrow 3. As the ratio between the spacing 26 of the conveyor trucks 1 Fig. l,

and the spacing 27 of the weights corresponds to the ratiobetween the speed 21 and the speed 20, and as the conveyor chains 5 are driven in such a way that the same time is required to cover the distances 26 and 27, the appurtenant supporting member remains above the centre of the corresponding conveyor truck 1 while the section 9 or 10 is being traversed.

The arrangement according to the present invention is extremely simple in design and reliable in operation. If

molds and the conveyor for weights is chosen exactly equal, the Weights are placed on the molds without sliding along them and the height of the molds can be altered as desired from zero to a maximum allowed by'the design.

Weights made of heavy ceramic material, zirconium oxide, corundum and the like, have the advantage that they keep their shape-that is to say, neither bend nor break-even if great changes in temperature occur. As the thermal conductivity of ceramic materials is many times lower than that of metals, the cooling effect on the liquid metals is also less. 1

Various changes and modifications may be made with out departing from the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

1. In a foundry having horizontal first conveyor means for carrying molds from a loading station past a pouring station and to a discharge station; apparatus for automatically placing weights on said molds prior to casting and for automatically lifting said weights from said molds subsequent to casting, comprising endless second conveyor means including a first section disposed above said first conveyor means and a second section disposed below said first conveyor means, drive means operatively connected to said first and second conveyor means for moving the same, said second conveyor means further including a third section arranged for downward movement past said first conveyor means at a first location between said loading and pouring stations and a fourth section arranged for upward movement past said first conveyor means at a second location between said pouring and discharge stations, and weight-supporting means carried by said second conveyor means, the directions of movement of said'third and fourth sections of said second conveyor means being at respective acute anglesto the direction of movement of said first conveyor means at said first and second locations, to enable said 4 weights when carried at said third section of said second conveyor means by said supporting means to be lifted off the latter and deposited successively on respective ones of said molds as the same pass said first location toward said pouring station, and to enable said weights when carried by said molds as the same pass said second location toward said discharge station to be lifted ofi the said molds by said supporting means at said fourth section of said second conveyor means, said drive means being constructed to ensure that the horizontal components of the downward and upward speeds of said third and fourth sections, respectively, of said second conveyor means are substantially equal to the speed of movement of said first conveyor means at-said first and second locations, respectively.

2. in a foundry according to claim 1; said acute angles being equal in magnitude, the uppermost parts of said third and fourth sections of said second conveyor means being disposed at an elevation above said first conveyor means substantially equal to the height of the highest mold carried by the same, and the lowermost parts of said third and fourth sections of said second conveyor means being disposed at substantially the same level as the molcl-carrying surface of said first conveyor means.

3. In a foundry according to claim 1; said second conveyor means comprising two conveyor chains arranged on opposite sides or". said first conveyor means and each including said first, second, third and fourth sections, said weight-supporting means comprising two sets of co ordinate support frames carried, respectively, by said chains and spaced uniformly along the latter.

References Cited in the file of this patent UNITED STATES PATENTS 501,331 Doolittle July 11, 1893 1,051,663 Ausbury Ian. 28, 1913 1,516,049 Luetscher Nov. 18, 1924 2,547,293 Vogel Apr. 3, 1951 2,570,927 Fellows et a1 Oct. 9, 1951 2,698,468 Zabel J an. 4, 1955 2,701,399 Underwood et al. Feb. 8, 1955 

